如何在swift中编写SFHFKeychainUtils

import Foundation

class SFHFKeychainUtils {
    class func getPasswordForUsername(username: String, andServiceName serviceName: String) -> String? {
        let query = [
            kSecClass: kSecClassGenericPassword,
            kSecAttrService: serviceName,
            kSecAttrAccount: username,
            kSecReturnData: kCFBooleanTrue!,
            kSecMatchLimit: kSecMatchLimitOne
        ] as CFDictionary
        
        var dataTypeRef: AnyObject?
        let status = SecItemCopyMatching(query, &dataTypeRef)
        
        if status == errSecSuccess {
            if let retrievedData = dataTypeRef as? Data {
                let password = String(data: retrievedData, encoding: .utf8)
                return password
            }
        }
        
        return nil
    }
    
    class func storeUsername(username: String, andPassword password: String, forServiceName serviceName: String) -> Bool {
        if let data = password.data(using: .utf8) {
            let query = [
                kSecClass: kSecClassGenericPassword,
                kSecAttrService: serviceName,
                kSecAttrAccount: username,
                kSecValueData: data
            ] as CFDictionary
            
            SecItemDelete(query)
            
            let status = SecItemAdd(query, nil)
            return status == errSecSuccess
        }
        
        return false
    }
    
    class func deleteItemForUsername(username: String, andServiceName serviceName: String) -> Bool {
        let query = [
            kSecClass: kSecClassGenericPassword,
            kSecAttrService: serviceName,
            kSecAttrAccount: username
        ] as CFDictionary
        
        let status = SecItemDelete(query)
        return status == errSecSuccess
    }
}

// 读取密码
if let password = SFHFKeychainUtils.getPasswordForUsername(username: "myUsername", andServiceName: "myService") {
    print("Password: \(password)")
} else {
    print("Password not found")
}

// 存储密码
if SFHFKeychainUtils.storeUsername(username: "myUsername", andPassword: "myPassword", forServiceName: "myService") {
    print("Password stored successfully")
} else {
    print("Failed to store password")
}

// 删除密码
if SFHFKeychainUtils.deleteItemForUsername(username: "myUsername", andServiceName: "myService") {
    print("Password deleted successfully")
} else {
    print("Failed to delete password")
}